Coincidentally, 8.0 has been my highest symptom-free and pharma-free test result since I first developed gout-like symptoms. I wasn’t taking any of the supplements you take.
It would be intersting if your symptom-free test results got much higher but I fear you won’t remain symptom-free much longer.
There’s not much difference between 6.9 and 8.0. Have you had enough test results to make a reasonable estimate of how noisy they are? My pharma-free results have been as low as 5.3.
It is common for gout sufferers to have long symptom-free periods. I don’t know of any demonstrated trigger or enabler for these periods.
When you have no symptoms while your UA is well into the danger zone, that suggests your immune system is currently not bothered by UA crystals. And we know that anti-UA antibodies contribute to UA crystalization in the same way that clouds are seeded by tiny particles. So you immune system being relaxed about UA crystals should enable higher amounts of UA to be retained in the blood. Trouble is, if the amount of UA gets high enough no help is needed for crystals to form and your immune system will sooner or later attack them if you are prone to gout.
There are other factors which inhibit crystallization such as high ambient temperature and (apparently) low amounts of iron in the blood.
Another reason for the amount of UA in your blood to rise would be a decreased ability to eliminate it. That doesn’t seem very likely unless you are slowly increasing your alcohol intake or something. I assume your supplements do not damage the kidneys.